1) No need for 3.7GB of node_modules to crank out a simple site
2) Single solution, easier to bring on junior developers and reason about application logic
3) Caching much easier, too many people think they need real-time push when NRT-polling + caching is far easier and more performant
Broadly speaking it's often a case of YAGNI. The JS ecosystem really does still suck for its complexity, I remember that every time I ramp up a new developer onto a React project. It's smoothed out with tooling but the litany of JSON configuration files and the mess created by hot-reload + proxying + microservices etc etc. Often just YAGNI.
People today don't remember the VB6 IDE days where you could slap a button on a Form, write a line of code for a MessageBox, and smash that play button with zero effort. JS development is often about working your way through a tangled spider-web of helper utilities and config files and JS modules at which point when it finally works you're afraid to rev anything.